Top forest managers and researchers offer public an education in how open, fire-resistant forests became deadly tinder boxes

A high-level group of researchers that have revolutionized forest management and the officials charged with implementing their ideas will join forces on Wednesday to explain the whole mess to the public.

Northern Arizona University professor Wally Covington will headline a “Walk in the Woods” gathering at 9 a.m. at the Payson Ranger Station, for a free, three-hour field trip to highlight the deadly impact of a century of grazing, logging and fire suppression.

The group will also include Payson Ranger District head Ed Armenta and Don Nunley, who heads up the effort to keep the local forests from burning down and taking scores of small communities with them.

“Most people don’t really know what a healthy forest looks like because we’re used to seeing them so thick,” said Bonnie Stevens, who represents Northern Arizona University’s Ecological Restoration Institute, which in the past two decades has transformed forest management goals by documenting the dramatic changes in the region’s forests in the past century.

“People see these thick, thick forests and think that’s the way they should be. On the tour, we’ll able to see some areas that are in good shape and some thickets — and talk about what would happen if fire went through.”

As though to underscore the point, half a dozen fires continue to burn throughout the region. The largest, the Schultz Fire, has charred more than 15,000 acres near Flagstaff, but on Monday was 65 percent contained. The bill for fighting it has so far topped $7 million, with 626 firefighters still deployed.

In the White Mountains near Hannigan Meadow, some 400 firefighters have largely contained the 6,300-acre Paradise Fire. Other crews are mopping up a five-acre fire that started along Highway 87 near mile marker 214 and other minor fires.

Wednesday’s tours by experts on forest management will help explain how the forest was transformed into a potentially deadly tinderbox, as a result of a series of management decisions that conspire to increase tree densities from about 50 per acre to about 1,000 per acre across millions of acres.

Ecologists and economists from NAU played a key role in forging a consensus about the need to dramatically reduce tree densities to restore forest health and diversity. Before Europeans arrived, Rim Country had open forests dominated by giant, centuries-old trees, with lots of grass and meadows.

A host of streams that now mostly run dry gurgled off the Mogollon Rim. Low-intensity ground fires burned through every five years or so, cleaning up the downed wood, rejuvenating the grass and not hurting the big, thick-barked, old-growth trees. Those pre-settlement forests were patchy and diverse, a mosaic of open areas and closed forests.

By contrast, widespread grazing that removed much of the grass followed by fire suppression that allowed thickets of saplings to spring up have dramatically changed the ecosystem. Now, major fires like the Dude and Rodeo-Chediski fires quickly climb up into the treetops and race along faster than a man can run, posing a grave danger to forest communities.

Moreover, the tons of dead wood on the ground cause such fires to burn so hot they can sterilize the soil.

NAU economists have done studies on one possible solution to the dangerous overgrowth, bring back the timber industry with long-term contracts that can supply mills that make a profit processing the small trees.

In the meantime, fires continue to roar through the unhinged system — sometimes restoring the balance, sometimes inflicting damage on the soil that will take decades to heal.

The Schultz Fire provides a case in point, said Stevens.

The fire started from an abandoned campfire along Schultz Pass Road north of Flagstaff and expanded rapidly. Firefighters had hoped that a thick, late snowpack would moderate fires this year, but this fire roared up the mountain above 10,000 feet, creating a crown fire that raced through even aspen stands.

But the fire might actually do more good than harm in some areas, said Stevens.

Aspen populations have crashed all across the Southwest, for reasons that still mystify biologists. Some blame global warming and the impact of a decade of drought in the Southwest. Some blame the lack of wildfires, noting that aspen are the first plants to return after a wildfire as they sprout from the roots.

Most of the big aspen stands around Flagstaff today are about 100 years old, which is when forest managers first started to seriously suppress wildfires. Some researchers wonder if a rise in the number of deer and elk have affected the aspen, by nibbling all their young shoots.

“So aspen is one of those trees that actually needs fire to come through,” said Stevens.

The key lies in whether the fire burned so hot that it killed the aspen roots from which new trees will sprout. And biologists won’t know that until they can study the burned area.

All of which means that Wednesday’s Walk in the Woods can provide a real education into the most deadly threat facing forest communities.